1 // Copyright 2012 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
7 #include "src/codegen.h"
8 #include "src/deoptimizer.h"
9 #include "src/full-codegen.h"
10 #include "src/safepoint-table.h"
15 const int Deoptimizer::table_entry_size_ = 8;
18 int Deoptimizer::patch_size() {
19 const int kCallInstructionSizeInWords = 3;
20 return kCallInstructionSizeInWords * Assembler::kInstrSize;
24 void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) {
25 Address code_start_address = code->instruction_start();
26 // Invalidate the relocation information, as it will become invalid by the
27 // code patching below, and is not needed any more.
28 code->InvalidateRelocation();
30 if (FLAG_zap_code_space) {
31 // Fail hard and early if we enter this code object again.
32 byte* pointer = code->FindCodeAgeSequence();
33 if (pointer != NULL) {
34 pointer += kNoCodeAgeSequenceLength;
36 pointer = code->instruction_start();
38 CodePatcher patcher(pointer, 1);
39 patcher.masm()->bkpt(0);
41 DeoptimizationInputData* data =
42 DeoptimizationInputData::cast(code->deoptimization_data());
43 int osr_offset = data->OsrPcOffset()->value();
45 CodePatcher osr_patcher(code->instruction_start() + osr_offset, 1);
46 osr_patcher.masm()->bkpt(0);
50 DeoptimizationInputData* deopt_data =
51 DeoptimizationInputData::cast(code->deoptimization_data());
53 Address prev_call_address = NULL;
55 // For each LLazyBailout instruction insert a call to the corresponding
56 // deoptimization entry.
57 for (int i = 0; i < deopt_data->DeoptCount(); i++) {
58 if (deopt_data->Pc(i)->value() == -1) continue;
59 Address call_address = code_start_address + deopt_data->Pc(i)->value();
60 Address deopt_entry = GetDeoptimizationEntry(isolate, i, LAZY);
61 // We need calls to have a predictable size in the unoptimized code, but
62 // this is optimized code, so we don't have to have a predictable size.
63 int call_size_in_bytes =
64 MacroAssembler::CallSizeNotPredictableCodeSize(isolate,
67 int call_size_in_words = call_size_in_bytes / Assembler::kInstrSize;
68 DCHECK(call_size_in_bytes % Assembler::kInstrSize == 0);
69 DCHECK(call_size_in_bytes <= patch_size());
70 CodePatcher patcher(call_address, call_size_in_words);
71 patcher.masm()->Call(deopt_entry, RelocInfo::NONE32);
72 DCHECK(prev_call_address == NULL ||
73 call_address >= prev_call_address + patch_size());
74 DCHECK(call_address + patch_size() <= code->instruction_end());
76 prev_call_address = call_address;
82 void Deoptimizer::FillInputFrame(Address tos, JavaScriptFrame* frame) {
83 // Set the register values. The values are not important as there are no
84 // callee saved registers in JavaScript frames, so all registers are
85 // spilled. Registers fp and sp are set to the correct values though.
87 for (int i = 0; i < Register::kNumRegisters; i++) {
88 input_->SetRegister(i, i * 4);
90 input_->SetRegister(sp.code(), reinterpret_cast<intptr_t>(frame->sp()));
91 input_->SetRegister(fp.code(), reinterpret_cast<intptr_t>(frame->fp()));
92 for (int i = 0; i < DoubleRegister::NumAllocatableRegisters(); i++) {
93 input_->SetDoubleRegister(i, 0.0);
96 // Fill the frame content from the actual data on the frame.
97 for (unsigned i = 0; i < input_->GetFrameSize(); i += kPointerSize) {
98 input_->SetFrameSlot(i, Memory::uint32_at(tos + i));
103 void Deoptimizer::SetPlatformCompiledStubRegisters(
104 FrameDescription* output_frame, CodeStubDescriptor* descriptor) {
105 ApiFunction function(descriptor->deoptimization_handler());
106 ExternalReference xref(&function, ExternalReference::BUILTIN_CALL, isolate_);
107 intptr_t handler = reinterpret_cast<intptr_t>(xref.address());
108 int params = descriptor->GetHandlerParameterCount();
109 output_frame->SetRegister(r0.code(), params);
110 output_frame->SetRegister(r1.code(), handler);
114 void Deoptimizer::CopyDoubleRegisters(FrameDescription* output_frame) {
118 void Deoptimizer::CopySIMD128Registers(FrameDescription* output_frame) {
119 for (int i = 0; i < DwVfpRegister::kMaxNumRegisters; ++i) {
120 double double_value = input_->GetDoubleRegister(i);
121 output_frame->SetDoubleRegister(i, double_value);
126 bool Deoptimizer::HasAlignmentPadding(JSFunction* function) {
127 // There is no dynamic alignment padding on ARM in the input frame.
134 // This code tries to be close to ia32 code so that any changes can be
136 void Deoptimizer::EntryGenerator::Generate() {
139 // Save all general purpose registers before messing with them.
140 const int kNumberOfRegisters = Register::kNumRegisters;
142 // Everything but pc, lr and ip which will be saved but not restored.
143 RegList restored_regs = kJSCallerSaved | kCalleeSaved | ip.bit();
145 const int kDoubleRegsSize =
146 kDoubleSize * DwVfpRegister::kMaxNumAllocatableRegisters;
148 // Save all allocatable VFP registers before messing with them.
149 DCHECK(kDoubleRegZero.code() == 14);
150 DCHECK(kScratchDoubleReg.code() == 15);
152 // Check CPU flags for number of registers, setting the Z condition flag.
153 __ CheckFor32DRegs(ip);
155 // Push registers d0-d13, and possibly d16-d31, on the stack.
156 // If d16-d31 are not pushed, decrease the stack pointer instead.
157 __ vstm(db_w, sp, d16, d31, ne);
158 __ sub(sp, sp, Operand(16 * kDoubleSize), LeaveCC, eq);
159 __ vstm(db_w, sp, d0, d13);
161 // Push all 16 registers (needed to populate FrameDescription::registers_).
162 // TODO(1588) Note that using pc with stm is deprecated, so we should perhaps
163 // handle this a bit differently.
164 __ stm(db_w, sp, restored_regs | sp.bit() | lr.bit() | pc.bit());
166 const int kSavedRegistersAreaSize =
167 (kNumberOfRegisters * kPointerSize) + kDoubleRegsSize;
169 // Get the bailout id from the stack.
170 __ ldr(r2, MemOperand(sp, kSavedRegistersAreaSize));
172 // Get the address of the location in the code object (r3) (return
173 // address for lazy deoptimization) and compute the fp-to-sp delta in
176 // Correct one word for bailout id.
177 __ add(r4, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
180 // Allocate a new deoptimizer object.
181 // Pass four arguments in r0 to r3 and fifth argument on stack.
182 __ PrepareCallCFunction(6, r5);
183 __ ldr(r0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
184 __ mov(r1, Operand(type())); // bailout type,
185 // r2: bailout id already loaded.
186 // r3: code address or 0 already loaded.
187 __ str(r4, MemOperand(sp, 0 * kPointerSize)); // Fp-to-sp delta.
188 __ mov(r5, Operand(ExternalReference::isolate_address(isolate())));
189 __ str(r5, MemOperand(sp, 1 * kPointerSize)); // Isolate.
190 // Call Deoptimizer::New().
192 AllowExternalCallThatCantCauseGC scope(masm());
193 __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate()), 6);
196 // Preserve "deoptimizer" object in register r0 and get the input
197 // frame descriptor pointer to r1 (deoptimizer->input_);
198 __ ldr(r1, MemOperand(r0, Deoptimizer::input_offset()));
200 // Copy core registers into FrameDescription::registers_[kNumRegisters].
201 DCHECK(Register::kNumRegisters == kNumberOfRegisters);
202 for (int i = 0; i < kNumberOfRegisters; i++) {
203 int offset = (i * kPointerSize) + FrameDescription::registers_offset();
204 __ ldr(r2, MemOperand(sp, i * kPointerSize));
205 __ str(r2, MemOperand(r1, offset));
208 // Copy VFP registers to
209 // double_registers_[DoubleRegister::kMaxNumAllocatableRegisters]
210 int double_regs_offset = FrameDescription::simd128_registers_offset();
211 for (int i = 0; i < DwVfpRegister::kMaxNumAllocatableRegisters; ++i) {
212 int dst_offset = i * kDoubleSize + double_regs_offset;
213 int src_offset = i * kDoubleSize + kNumberOfRegisters * kPointerSize;
214 __ vldr(d0, sp, src_offset);
215 __ vstr(d0, r1, dst_offset);
218 // Remove the bailout id and the saved registers from the stack.
219 __ add(sp, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
221 // Compute a pointer to the unwinding limit in register r2; that is
222 // the first stack slot not part of the input frame.
223 __ ldr(r2, MemOperand(r1, FrameDescription::frame_size_offset()));
226 // Unwind the stack down to - but not including - the unwinding
227 // limit and copy the contents of the activation frame to the input
228 // frame description.
229 __ add(r3, r1, Operand(FrameDescription::frame_content_offset()));
231 Label pop_loop_header;
232 __ b(&pop_loop_header);
235 __ str(r4, MemOperand(r3, 0));
236 __ add(r3, r3, Operand(sizeof(uint32_t)));
237 __ bind(&pop_loop_header);
241 // Compute the output frame in the deoptimizer.
242 __ push(r0); // Preserve deoptimizer object across call.
243 // r0: deoptimizer object; r1: scratch.
244 __ PrepareCallCFunction(1, r1);
245 // Call Deoptimizer::ComputeOutputFrames().
247 AllowExternalCallThatCantCauseGC scope(masm());
249 ExternalReference::compute_output_frames_function(isolate()), 1);
251 __ pop(r0); // Restore deoptimizer object (class Deoptimizer).
253 // Replace the current (input) frame with the output frames.
254 Label outer_push_loop, inner_push_loop,
255 outer_loop_header, inner_loop_header;
256 // Outer loop state: r4 = current "FrameDescription** output_",
257 // r1 = one past the last FrameDescription**.
258 __ ldr(r1, MemOperand(r0, Deoptimizer::output_count_offset()));
259 __ ldr(r4, MemOperand(r0, Deoptimizer::output_offset())); // r4 is output_.
260 __ add(r1, r4, Operand(r1, LSL, 2));
261 __ jmp(&outer_loop_header);
262 __ bind(&outer_push_loop);
263 // Inner loop state: r2 = current FrameDescription*, r3 = loop index.
264 __ ldr(r2, MemOperand(r4, 0)); // output_[ix]
265 __ ldr(r3, MemOperand(r2, FrameDescription::frame_size_offset()));
266 __ jmp(&inner_loop_header);
267 __ bind(&inner_push_loop);
268 __ sub(r3, r3, Operand(sizeof(uint32_t)));
269 __ add(r6, r2, Operand(r3));
270 __ ldr(r6, MemOperand(r6, FrameDescription::frame_content_offset()));
272 __ bind(&inner_loop_header);
273 __ cmp(r3, Operand::Zero());
274 __ b(ne, &inner_push_loop); // test for gt?
275 __ add(r4, r4, Operand(kPointerSize));
276 __ bind(&outer_loop_header);
278 __ b(lt, &outer_push_loop);
280 // Check CPU flags for number of registers, setting the Z condition flag.
281 __ CheckFor32DRegs(ip);
283 __ ldr(r1, MemOperand(r0, Deoptimizer::input_offset()));
284 int src_offset = FrameDescription::simd128_registers_offset();
285 for (int i = 0; i < DwVfpRegister::kMaxNumRegisters; ++i) {
286 if (i == kDoubleRegZero.code()) continue;
287 if (i == kScratchDoubleReg.code()) continue;
289 const DwVfpRegister reg = DwVfpRegister::from_code(i);
290 __ vldr(reg, r1, src_offset, i < 16 ? al : ne);
291 src_offset += kDoubleSize;
294 // Push state, pc, and continuation from the last output frame.
295 __ ldr(r6, MemOperand(r2, FrameDescription::state_offset()));
297 __ ldr(r6, MemOperand(r2, FrameDescription::pc_offset()));
299 __ ldr(r6, MemOperand(r2, FrameDescription::continuation_offset()));
302 // Push the registers from the last output frame.
303 for (int i = kNumberOfRegisters - 1; i >= 0; i--) {
304 int offset = (i * kPointerSize) + FrameDescription::registers_offset();
305 __ ldr(r6, MemOperand(r2, offset));
309 // Restore the registers from the stack.
310 __ ldm(ia_w, sp, restored_regs); // all but pc registers.
311 __ pop(ip); // remove sp
312 __ pop(ip); // remove lr
314 __ InitializeRootRegister();
316 __ pop(ip); // remove pc
317 __ pop(ip); // get continuation, leave pc on stack
320 __ stop("Unreachable.");
324 void Deoptimizer::TableEntryGenerator::GeneratePrologue() {
325 // Create a sequence of deoptimization entries.
326 // Note that registers are still live when jumping to an entry.
328 for (int i = 0; i < count(); i++) {
329 int start = masm()->pc_offset();
331 __ mov(ip, Operand(i));
333 DCHECK(masm()->pc_offset() - start == table_entry_size_);
340 void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) {
341 SetFrameSlot(offset, value);
345 void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) {
346 SetFrameSlot(offset, value);
350 void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
351 DCHECK(FLAG_enable_ool_constant_pool);
352 SetFrameSlot(offset, value);
356 double FrameDescription::GetDoubleRegister(unsigned n) const {
357 DCHECK(n < 2 * arraysize(simd128_registers_));
358 return simd128_registers_[n / 2].d[n % 2];
362 void FrameDescription::SetDoubleRegister(unsigned n, double value) {
363 DCHECK(n < 2 * arraysize(simd128_registers_));
364 simd128_registers_[n / 2].d[n % 2] = value;
368 simd128_value_t FrameDescription::GetSIMD128Register(unsigned n) const {
369 DCHECK(n < arraysize(simd128_registers_));
370 return simd128_registers_[n];
374 void FrameDescription::SetSIMD128Register(unsigned n, simd128_value_t value) {
375 DCHECK(n < arraysize(simd128_registers_));
376 simd128_registers_[n] = value;
380 int FrameDescription::double_registers_offset() {
381 return OFFSET_OF(FrameDescription, simd128_registers_);
385 int FrameDescription::simd128_registers_offset() {
386 return OFFSET_OF(FrameDescription, simd128_registers_);
392 } } // namespace v8::internal